eg:images("input.png").encode("output.jpg", {operation:50})
Encoding and save the current image to a file, if the type is not specified, type well be automatically determined according to the file, config is image setting. eg: { operation:50 }
编码并保存当前图像到 file ,如果type未指定,则根据 file 自动判断文件类型，config为图片设置，目前支持设置JPG图像质量